Hepatitis B surface antigen (HB.sub.s Ag) has been shown to be effective as a vaccine against hepatitis B disease. The usual source of this antigen is plasma obtained from donors, e.g., by phasmaphoresis. As a result the supply of plasma containing this antigen is uncertain and expensive as most plasma is free of HB.sub.s Ag.
Attempts have been made heretofore to grow HB.sub.s Ag in vitro. For example, it is known that in vitro tissue cultures of human hepatoma cells produce HB.sub.s Ag in vitro although in only trace amounts and with no detectable complement fixation titer. Humans infected with hepatitis B disease, on the other hand, produce large amounts of HB.sub.s Ag--about 10.sup.13 particles/ml with a complement fixation titer of about 256.